Intel Xeon E7 4820 v3 's Advantages
Lower TDP (115W vs 250W)
Xeon 6766E 's Advantages
Released 9 years late
Higher specification of memory (6400 vs 1866)
Newer PCIe version (5 vs 3)
Larger L3 cache size (108MB vs 25MB)
More modern manufacturing process (5nm vs 22nm)